An UPLC-MS/MS method for the determination of EAI045 in plasma and tissues and its application to pharmacokinetic and distribution studies in rats

EAI045 represents a fourth generation allosteric EGFR TKI compound which targets T790M and C797S EGFR mutants. The study reported herein describes a method to explore the distribution of EAI045 in rat tissues as well as to quantify it in plasma. The method used here is an ultra-performance liquid chromatography-tandem mass spectrometry with high sensitivity and selectivity. An ACQUITY UPLC BEN HILIC column with dimensions of 2.1 x 100 mm, 1.7 mu m was used to separate the analytes and IS. As mobile phase acetonitrile as well as 0.1 % of formic acid/water was used combined with an elution gradient and 0.40 mL/min flow rate. This eluent was also used for electrospray ionization in positive ion mode. A mode on multiple reactions monitoring (MRM) was also employed in the quantification. This quantification included the use of targeted segment ions with m/z 384.1 -> 100.8 for EAI045, and m/z 285.1 -> 193.3 for IS, respectively. It was found that the linearity of this method was appropriate and the concentration range could be kept within a range of 2-2000 ng/mL for EAI045 in rat plasma and tissues. The level of EAI045 was found to be highest in the liver, followed by kidneys, lungs and heart. Furthermore, the results provided evidence that EAI045 could be absorbed quickly and distributed widely in different tissue types.